Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

A portable communication device, such as a cellular telephone,
communicates via a wireless communication link with a remote user
interface device, such as a hands-free interface. The portable
communication device and the remote user interface device each comprises
a motion sensor, by which each device can determine motion of the device
with respect to the earth. The devices may share, via the wireless
communication link, motion messages. The wireless communication link may
be terminated as a function of the motion of the devices. After the
wireless communication link is terminated, the remote user interface
device may automatically enter a low-power mode.

Claims:

1. A system comprising: a portable communication device comprising: a
first transceiver operable to exchange wireless signals with a cellular
network, a second transceiver operable to wirelessly communicate with a
remote user interface device via a wireless communication link, and a
first motion sensor that generates a first motion signal as a function of
motion of the portable communication device with respect to the earth;
and the remote user interface device, comprising: a third transceiver for
communicating via the wireless communication link with the second
transceiver, and a second motion sensor that generates a second motion
signal as a function of motion of the remote user interface device with
respect to the earth; wherein one of the portable communication device
and the remote user interface device terminates the wireless
communication link as a function of the first and second motion signals.

2. The system as recited in claim 1, wherein the remote user interface
device is further operable automatically to enter a low-power mode after
the wireless communication link is terminated.

3. The system as recited in claim 2, wherein to enter a low-power mode
comprises to turn off the remote user interface device.

4. The system as recited in claim 1 wherein the first motion sensor is an
accelerometer.

5. The system as recited in claim 1 wherein the second motion sensor is
an accelerometer.

6. The system as recited in claim 1, wherein the remote user interface
device further comprises a microphone and a speaker.

7. The system as recited in claim 1 wherein the portable communication
device is operable to generate a motion message as a function of the
first motion signal, wherein the remote user interface device terminates
the wireless communication link, and wherein terminating the
communication link as a function of the first second motion signal
comprises terminating the communication link as a function of the motion
message.

8. A method executed by a processor in a remote user interface device,
the remote user interface device comprising a motion sensor operably
connected to the processor, the remote user interface device further
having a wireless communication link with a portable communication
device, the method comprising: receiving a motion message from the
portable communication device, the motion message indicating whether the
portable communication device is in motion with respect to the earth;
receiving from the motion sensor a motion signal, the motion signal being
a function of motion of the remote user interface device with respect to
the earth; and terminating the communication link as a function of the
motion message and the motion signal.

9. The method of claim 8, wherein terminating the communication link as a
function of the motion message and the motion signal comprises:
determining that the remote user interface device is substantially
stationary with respect to the earth as a function of the motion signal;
determining that the portable communication device is in motion with
respect to the earth as a function of the motion message, and thereafter
terminating the communication link.

10. The method of claim 9, wherein the motion message is a first motion
message, the motion signal is a first motion signal, the method further
comprising, after determining that the portable communication device is
in motion with respect to the earth as a function of the first motion
message: after a delay period, receiving a second motion message from the
portable communication device, the second motion message indicating
whether the portable communication device is in motion with respect to
the earth; after the delay period, receiving from the motion sensor a
second motion signal, the second motion signal being a function of motion
of the remote user interface device with respect to the earth;
determining that the remote user interface device is substantially
stationary with respect to the earth as a function of the second motion
signal; and determining that the portable communication device is in
motion with respect to the earth as a function of the second motion
message.

11. The method of claim 8, wherein the motion message is a first motion
message, the motion signal is a first motion signal, the method further
comprising, after an extended period of time of at least ten minutes,
receiving a second motion message from the portable communication device,
the second motion message indicating whether the portable communication
device is in motion with respect to the earth; after the extended period
of time, receiving from the motion sensor a second motion signal, the
second motion signal being a function of motion of the remote user
interface device with respect to the earth; determining that the portable
communication device is substantially stationary with respect to the
earth as a function of the first and second motion messages; determining
that the remote user interface device is substantially stationary with
respect to the earth as a function of the first and second motion
signals; and thereafter terminating the communication link.

12. The method of claim 8, further comprising, after terminating the
communication link, entering a low-power mode.

13. The method of claim 8, wherein terminating the communication link
comprises sending a request to the portable communication device to
terminate the communication link.

14. A method executed by a processor in a portable communication device,
the portable communication device comprising a motion sensor operably
connected to the processor, the portable communication further having a
wireless communication link with a remote user interface device, the
method comprising: receiving a motion message from the remote user
interface device, the motion message indicating whether the remote user
interface device is in motion with respect to the earth; receiving from
the motion sensor a motion signal, the motion signal being a function of
motion of the portable communication device with respect to the earth;
and terminating the communication link as a function of the motion
message and the motion signal.

15. An electronic device comprising: a processor; a motion sensor; a
transceiver operable to communicate wirelessly over a short-range
communication link with a second electronic device; wherein the processor
is operable to: receive via the transceiver a motion message from the
second electronic device; receive from the motion sensor a motion signal,
the motion signal being a function of motion of the electronic device
with respect to the earth; and terminate the communication link as a
function of the motion message and the motion signal.

16. The electronic device of claim 15, wherein the electronic device is a
portable communication device.

18. The electronic device of claim 15, wherein the processor is further
operable to: determine that the second electronic device is substantially
stationary with respect to the earth as a function of the motion signal;
determining that the electronic device is in motion with respect to the
earth as a function of the motion message, and thereafter terminating the
communication link.

19. The electronic device of claim 15, further comprising a speaker and a
microphone operably connected to the processor.

20. The electronic device of claim 15, further comprising a second
transceiver operable to communicate wirelessly with a cellular telephone
network over a range longer than the short-range communication link.

Description:

TECHNICAL FIELD

[0001] The present disclosure relates generally to portable wireless
communication devices, such as cellular telephones, and more particularly
the use of such communication devices linked wirelessly to a remote user
interface device.

BACKGROUND

[0002] Portable communication devices, such as cellular telephones, are in
common use. Wireless communication devices such as cellular telephones
enjoy the convenience of portability. Experience has shown that some
users choose to operate a wireless communication device while driving an
automobile. Some forms of operation have drawn criticism, citing concerns
such as the user using one hand to hold the phone against an ear, thereby
making driving an automobile difficult and potentially hazardous, because
the hand used for the cellular telephone is not available to operate
other controls of the motor vehicle. Dialing a number in a cellular
telephone is another commonly expressed concern, in that dialing may be
distracting to the driver.

[0003] Remote user interface devices have been developed to facilitate a
driver's use of a cellular telephone, while still having both hands
available to operate the motor vehicle. Such devices may be clipped to
the sun visor or other component of the motor vehicle (some may even be
"built-in" to the motor vehicle) in a location in which the user may both
speak into the device and hear sounds emitted from a speaker therein. The
remote user interface device contains a transceiver that wirelessly
interfaces with the cellular telephone by a communication protocol, such
as, for example, the IEEE standard 802.11 or 802.15.1--2002 (one
implementation of which is the Bluetooth® wireless technology
developed by Bluetooth SIG, Inc., Bellevue, Wash., U.S.A.). While the
cellular telephone is within range, any incoming call utilizes the remote
user interface device to communicate with the driver. That is, the audio
received by the cellular telephone via the cellular network is fed
through a speaker in the remote device for hearing by the driver. When
the driver speaks, a microphone in the remote device speaker receives
that sound and transmits an audio signal via the wireless link to the
cellular telephone for relaying onto the cellular network.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004]FIG. 1 is a block diagram of a wireless communication system that
has a portable communication device and a remote user interface device;

[0005]FIG. 2 is a flowchart of a process that may be carried out by a
remote user interface device; and

[0006]FIG. 3 is a flowchart of an alternative process that may be carried
out by a remote user interface device.

DETAILED DESCRIPTION

[0007] Many remote user interface devices (typically those that are not
"built-in" to the motor vehicle) are powered by a power supply (such as a
rechargeable battery) that is independent of the motor vehicle. As a
result, such remote user interface devices may not automatically turn off
(or otherwise enter a low-power mode) when the vehicle ignition switch is
in the off position. As a consequence, the power stored in the power
supply of the remote user interface device may be consumed unnecessarily
if the driver forgets to separately turn off the remote user interface
device upon exiting the vehicle.

[0008] Another concern may occur when, after parking a vehicle with the
remote user interface device left on, the cellular telephone remains
within range of the remote user interface device. This can occur, for
example, when the vehicle is parked in a garage attached to the user's
house and although the user takes the cellular telephone inside the
house, the cellular telephone is still within range of the remote user
interface device. The communication link between those two devices can
remain in effect and incoming telephone calls may continue to be routed
by the cellular phone to the unattended remote user interface device in
the vehicle. Not only can such a scenario result in an unnecessary
consumption of power in the remote user interface device's power supply
(which may be but need not be independent of the motor vehicle), there
can also be inconvenience to the user as cellular communications may be
diverted from the cellular telephone to the remote user interface device.

[0009] The present system includes a wireless portable communication
device, such as but not limited to, cellular telephones and smart phones.
The portable communication device may be handheld, that is, sized to be
held or carried in a human hand. The wireless portable communication
device may include two wireless communication transceivers: a
conventional cellular transceiver and another relatively low-power
transceiver operable to communicate with a remote user interface device.
(As used herein, when a component is "operable to" perform a function,
the component is configured to execute that function, i.e., is capable of
performing or carrying out that function. Components that are "operably
connected" to one another are in a relation such that a physical,
mechanical and/or electronic activity in one can affect the operation of
the other.) The portable communication device has a motion sensor to
detect when the portable communication device is moving with respect to
the earth. The remote user interface device also has a motion sensor to
detect when the remote user interface device is moving with respect to
the earth. As described in more detail below, the wireless communication
link between the portable communication device and the remote user
interface device is terminated when a determination is made that the
portable communication device is moving and the remote user interface
device is stationary. That determination may be made automatically by a
processor in the portable communication device, or in the remote user
interface device, or both.

[0010] For purposes of simplicity, the concepts may be described or
understood in a scenario in which the portable communication device is a
cellular phone and the remote user interface device is sometimes called a
"car kit" or a "hands-free" interface or device, that installs in (or is
built into) a motor vehicle and allows hands-free use of the cellular
telephone by a user, such as the driver or a passenger. The remote user
interface device is "remote" in the sense that it is typically not a
unitary structure with the portable communication device, that it
responds to wireless signals from the portable communication device,
and/or that it may be under the control of the portable communication
device. The remote user interface device may include functionality in
addition to that described, such as Global Positioning System
functionality. The portable communication device and the remote user
interface may each include a power supply, which for simplicity may be
described as a battery. Importantly, the concepts may be applicable to a
scenario in which the power supply for the remote user interface is not
independent of the motor vehicle, e.g., where a car kit is powered by a
motor vehicle's battery. The portable communication device and the remote
user interface device each include a motion sensor, which will for
simplicity be described as an accelerometer. In general, the motion
sensor generates an electrical signal as a function of (or based on) a
position or a change in position or an acceleration (which are related to
one another mathematically). For purposes of simplicity, it may be said
that a motion sensor generates a motion signal as a function of motion
with respect to the earth. In general, the motion signal indicates
whether or not there is motion, and may also include information about
the motion (e.g., its magnitude, direction, rate of change, etc.).

[0011] The portable communication device and the remote user interface
device include control circuitry that (typically periodically) evaluates
the signal from the respective motion sensor. One of those devices sends
a message to the other device indicating whether the sending device is in
motion. At least one of the devices, such as the device receiving that
message, determines whether the remote user interface device is moving or
not, and whether the portable communication device is moving or not. When
the user has exited a parked vehicle, the remote user interface device is
generally not moving but the portable communication device generally is
moving. When at least one of the devices determines that the remote user
interface device is not moving and that the portable communication device
is moving, the wireless link between the portable communication device
and the remote user interface device is terminated. The remote user
interface device may also enter a power-conserving mode. A
power-conserving mode can be any mode of operation that reduces power
consumption. The remote user interface device may, for example, turn off
completely or enter a standby mode until communication with a portable
communication device occurs again.

[0012] Note that if both the portable communication device and the remote
user interface device are in motion, it may be assumed that both devices
are still being carried by the motor vehicle, and that motor vehicle is
moving. Similarly, when both the cellular telephone and the remote user
interface device have stopped moving, it may be assumed that the motor
vehicle is stopped momentarily, such as at a traffic signal. If both
devices are stationary for a predefined--and typically prolonged--period
of time, such as two hours, such as when both are left in a parked
vehicle, then the communication link may be disconnected and the remote
user interface device may enter the power-conserving mode. (As used
herein, a period of time in a method is "predefined" in the sense that it
is typically set--expressly or inferentially--before the method begins.
One example of a predefined period of time is a default period of time
embedded within the software that controls the monitoring of the motion
of the devices. Another example of a predefined period of time is a
period of time selected by a user and stored in a memory element of one
or both devices.)

[0013] Referring initially to a communication system 100 in FIG. 1, a
wireless portable communication device 102, such as a cellular telephone,
illustratively includes a housing 104 which may be any of several
different types commonly used for cellular telephones and other portable
electronic devices. A power supply, represented as a battery 106, is
carried within the housing 104 for supplying power to the internal
components. The battery 106 may be (for example) a replaceable or a
rechargeable battery, which supplies power via a battery interface 108.
The housing 104 contains circuitry (not all of which is shown in FIG. 1),
which typically includes a processor 110, which may be embodied as a
microprocessor that controls many of the functions of the portable
communication device 102. The portable communication device 102 further
includes one or more memory elements 112, which store data used by and
instructions executed by the processor 110. The processor may receive
user input from or provide user output to one or more user interfaces
114, such as a display, a keyboard, a touch pad, a touch screen, a button
and the like. An audio input device, such as a microphone 116, and an
audio output device, such as a speaker 118, may also be operably
connected to the processor 110. Not all operable connections are depicted
in FIG. 1.

[0014] In the example of FIG. 1, cellular telephone communications may be
performed through a first, or cellular, transceiver 120, which includes a
wireless signal receiver and a wireless signal transmitter that are
connected to a first antenna 122. The first antenna 122 may be carried
within the upper portion of the housing 104 for sending and receiving
signals via a first wireless communication link 124 with a cellular
telephone network 126. For example, the first transceiver 120 may
transmit on a cellular band, e.g., 800-900 MHz, at cellular power levels,
e.g., 0.2-0.6 watts.

[0015] The portable communication device 102 may also include a second
transceiver 128 connected to a second antenna 130. The second transceiver
128 may comply with the Bluetooth® communication protocol stated in
Specification of the Bluetooth System, Master Table of Contents &
Compliance Requirements, Version 2.1, November 2005 and Specification of
the Bluetooth System, Profiles, version 1.1, Feb. 22, 2001; both
published by Bluetooth SIG, Inc. The second transceiver 128 may transmit
at much lower power levels than the first transceiver 120. In general,
the Bluetooth® communication protocol is intended for relatively
short-range, e.g., 100-200 meters, wireless communication. Bluetooth®
enabled devices operate around 2.4 GHz at one of number of different
power levels, including a 0 dBm level transmit power (e.g., 1 milliwatt)
in which the communication has a 10-meter range, and a 20 dBm transmit
power (e.g., 100 milliwatts) which has a 100-meter range. This
communication protocol is a multiple access system, which uses a
frequency-hopped spread spectrum with time division duplex. The frequency
hopping occurs at approximately 1600 hops/sec. Each Bluetooth® device
has a unique 48-bit address. The second transceiver 128 wirelessly
communicates with external devices which interface a user to the portable
communication device 102. Although the present concepts are being
described in the context of a cellular telephone and the Bluetooth®
communication protocol, the concepts described herein can be used with
other types of portable communication devices and other wireless user
interface protocols, such as defined by IEEE standard 802.11. Further,
the communication link may be a wireless communication link of any kind
and any range, although a typical range may be less than 200 meters (some
devices, for example have ranges of 100 meters or 10 meters). Beyond the
short range of communication, the wireless communication link may not be
reliable or sustainable or capable of being established. This wireless
communication link is short-range in the sense that it is typically
significantly shorter than the range of the first wireless communication
link 124.

[0016] The second transceiver 128 communicates with a remote user
interface device 132, such as an apparatus that allows hands-free use of
a cellular telephone while the user is driving a motor vehicle. The
remote user interface device 132 illustratively includes a housing 134
that contains or otherwise provides a framework for other components of
the remote user interface device 132. As depicted in FIG. 1, the remote
user interface device 132 may be powered by a battery 136 that may be
independent of any other power source. The remote user interface device
132 further includes a remote transceiver 138 that is connected to a
remote antenna 140. The remote transceiver 138 and remote antenna 140 are
operable to communicate wirelessly, using the same communication protocol
(e.g. Bluetooth®), to exchange signals via a second (short-range)
communication link 142 with the second antenna 130 and the second
transceiver 128 in the portable wireless communication device 102. A
second processor 144 controls many of the functions of the remote user
interface device 132. The remote user interface device 132 may also
include one or more memory elements (not shown in FIG. 1) that store data
or instructions for execution by the second processor 144. The second
processor 144 may also be operably connected to one or more user
interface elements (not shown in FIG. 1), such as a display, button, etc.
The remote user interface device 132 may also include a microphone 146,
and a speaker 148, through which a user may make or receive audible
communication.

[0017] The wireless communication device 102 and the remote user interface
device 132 may store control software for implementing the methods
described herein. In addition, wireless communication device 102 and the
remote user interface device 132 include motion sensors 150, 152. For
purposes of simplicity, the motion sensors 150, 152 will be referred to
as accelerometers, but accelerometers are examples of motion sensors and
the disclosure is not limited to the use of accelerometers to detect
motion. Further, the accelerometers 150, 152 can be any kind of devices
that are responsive to position, change in position or acceleration
including, but not limited to, microelectromechanical systems (MEMS)
based accelerometers. The wireless communication device 102 includes a
first accelerometer 150, which detects when the remote communication
device is moving and produces a first motion signal that indicates
whether or not motion is occurring. The motion signal may be generated
continuously or in response to a request such as a polling request. Such
motion can occur by a user carrying the communication device 102 while
walking, for example, or by movement of an automobile in which that
device is located. The first motion signal produced by the first
accelerometer 150 in response to motion is provided as an input to the
processor 110. As will be discussed below, the motion signal may be
indicative of one or more characteristics of motion, including (but not
necessarily limited to): whether a device is in a moving state or a
non-moving state; whether a device has changed state (e.g., from moving
to non-moving or vice versa); whether a motion has occurred that is
significant; or any combination thereof.

[0018] The remote user interface device 132 comprises a second
accelerometer 152, connected to the processor 144. The second
accelerometer 152 produces a second motion signal indicating when the
remote user interface device 132 is moving. When the remote user
interface device 132 is fastened to a component within a motor vehicle,
the second motion signal from the second accelerometer indicates movement
when that vehicle is in motion. The accelerometers 150 and 152 may be,
but need not be, of the same kind.

[0019] The two motion sensors, in this implementation accelerometers 150
and 152, are employed to determine when a user, who for purposes of
illustration will be represented as the driver, has exited the motor
vehicle and has taken the portable communication device 102 from the
vehicle. An illustrative process for doing that may be carried out by the
remote user interface device 132 (the process may be may be implemented
in software and executed by processor 144) is depicted in FIG. 2. At the
outset of the process (200), the remote user interface device 132 may be
activated, such as by the driver manually turning on the remote user
interface device 132. The transceiver 138 performs a procedure specified
by the respective communication protocol, such as Bluetooth®, to
establish the second communication link 142 with the portable
communication device 102 (202). The processor 144 may perform some
initialization (204), during which a variable, designated the "Filter
Variable," and a software implemented timer are set to zero (as will be
mentioned below, there may be two distinct timers, and both may be
initialized). The functions of those elements will be described
subsequently.

[0020] The process may include waiting for a delay period, that is, a
predefined period of time (typically significantly shorter than the
typically prolonged predefined period of time mentioned above), for
example, two seconds (206). The timer is used to determine whether this
delay period has elapsed or not. The effect of this two-second delay
period is that subsequent loops of the process will occur at two-second
intervals (other delay periods or no delay may be used, however). This
delay period defines an interval at which a motion indication is
periodically requested from the portable communication device 102. After
delaying for the predefined period of time, the remote user interface
device 132 sends a request message to the portable communication device
102 requesting motion information from the first accelerometer 150 (208).

[0021] At the portable communication device 102, the second antenna 130
and second transceiver 128 receive the request and convey the request to
the processor 110. The processor 110 receives a motion signal from the
accelerometer 150 which indicates whether the portable communication
device 102 is moving. In a typical embodiment, the processor 110 may
process the motion signal, to determine the validity of the motion
signal. For example, the processor 110 may compare the motion signal to a
threshold, and may determine that any motion having a magnitude below a
particular threshold is insignificant or otherwise not a good indication
of whether the portable communication device 102 (or the motor vehicle in
which it is being carried) is moving. Such a threshold may include a
default limit or a motion sensitivity setting selected by a user.

[0022] The portable communication device 102 transmits (via transceiver
128 and antenna 130) a motion message to the remote user interface device
132, which receives the motion message (210) via its own transceiver 138
and antenna 140. The motion message, which is a function of the motion
signal from the accelerometer 150, indicates whether the portable
communication device 102 is in motion. The motion message may comprise a
binary "motion" or "no motion" indication. Alternatively, the motion
message may carry a value indicating the intensity of any motion or the
magnitude of acceleration of the portable communication device (which can
provide an indication of whether the portable communication device 102 is
in motion). In another variation, the motion message may include
information about the direction of motion. In yet another variation, the
motion message may carry a binary indication that the device has changed
from a moving state to a non-moving state or vice versa. The concept is
not limited to a motion message having any particular kind of indication
with respect to any particular characteristic of motion.

[0023] After receiving the motion message, the remote user interface
device 132 determines whether the remote user interface device 132 is in
motion. The processor 144 of the remote user interface device 132
receives a motion signal from the accelerometer 152, which indicates
whether the remote user interface device 132 is moving. The processor 144
may process this motion signal for validity (e.g., compare the motion
signal from the accelerometer 152 to a threshold), although this
processing is not depicted in FIG. 2. The processor 144 determines, as a
function of the motion signal from its accelerometer 152, whether the
remote user interface device 132 is moving (214). The processor 144
further determines, as a function of the motion messages received from
the portable communication device 102, whether the portable communication
device 102 is moving (216). When the processor 144 of the remote user
interface device 132 determines that the remote user interface device is
in motion, the timer keeping track of the delay period is reset to zero
(218). The motion of the user interface device 132 may indicate that the
vehicle itself is in motion, and while the vehicle is in motion, the
second communication link 142 should remain established. (There may be
circumstances under which the user interface device 132 is moving and the
portable communication device 102 is not, and the relative movement of
the devices 102, 132 causes a distance between them to grow, thereby
causing the communication link 142 between them to be terminated because
the devices are out of range. Termination of the link 142 due to the
devices going out of range with one another is not explicitly depicted in
FIG. 2.) The Filter Variable is reset to zero (220) and the process
loops.

[0024] In the event the processor 144 determines that the remote user
interface device 132 is not moving and that the portable communication
device 102 likewise is not moving, the processor 144 determines whether
the lack of motion of both devices 102, 132 has occurred for an extended
period of time (222). The extended period of time is "extended" in the
sense that it is generally substantially longer than other time periods
used in the process. For purposes of illustration, the extended time
period may be two hours, but this duration is not mandatory. Typical
durations may be (for example) from ten minutes to four hours, and the
duration of the extended period may, in some embodiments, be specified by
a user. A second software implemented timer, distinct from the timer that
keeps track of the delay period, may keep track of the extended period.
This second timer, like the timer that keeps track of the delay period,
may be reset when the processor 144 determines that the remote user
interface device 132 is moving. This second timer may be started when the
processor 144 determines that the remote user interface device 132 is not
moving (assuming that this timer has not been started already). In the
event that extended period of time has not elapsed, the delay period
timer may be reset (218) (with the extended period timer not being reset
unless the remote user interface device 132 is moving), the Filter
Variable is reset (220) and the process loops. When the remote user
interface device 132 and the portable communication device 102 are not
moving, but the extended period of time has not elapsed, the lack of
motion may be due to (for example) a temporary stoppage of traffic.

[0025] In the event the remote user interface device 132 and the portable
communication device 102 are not moving and the extended period has
elapsed, the processor 144 may terminate the communication link 142
(224). The processor 144 may terminate the communication link 142 itself
or may transmit a request to the portable communication device 102 to
terminate the communication link. After termination of the link, the
processor 144 may cause the remote user interface device 132
automatically to enter a low-power mode (226), which may comprise (for
example) the remote user interface device 132 turning off or entering a
standby mode (in which some or all functionality is suspended and power
consumption is thereby reduced) until communication with a portable
communication device 102 occurs again.

[0026] In the event that the remote user interface device 132 is not
moving but the portable communication device 102 is moving, it may be
that the portable communication device 102 may have been removed from a
stationary vehicle and is being carried by a user. The Filter Variable
can help determine whether this is the case. In a simple implementation,
the Filter Variable counts a number of loops, such as two loops. In the
event that the remote user interface device 132 is not moving, and the
portable communication device 102 is moving, and this has been the case
for two consecutive loops, then the processor 144 may terminate the
communication link 142 (224) and put the remote user interface device 132
into a low-power mode (226). Otherwise, the processor 144 may increment
the Filter Variable and reset the delay timer (230), and the process
loops. The selection of two loops for a Filter Variable is merely for
purposes of illustration, and it should be noted that the Filter Variable
is optional.

[0027] Many stages in the process depicted in FIG. 2, although being
depicted as being carried out by the remote user interface device 132,
may also be carried out by the portable communication device 102. In
brief, the processor 110 of the portable communication device 102 may
(after a delay period) determine (based upon a motion signal from
accelerometer 150) whether the portable communication device 102 is
moving, and may also determine whether the remote user interface device
132 is moving (based upon a motion message from the remote user interface
device 132). When both devices 102, 132 are not in motion (i.e., are
substantially stationary), and the lack of motion has persisted for an
extended period of time, the processor 110 may terminate the
communication link 142. Also, in an event the portable communication
device 102 is moving but the remote user interface device 132 is not, the
processor 110 may terminate the communication link 142. Upon termination
of the communication link 142, the remote user interface device 132 may
enter a low-power mode, and the portable communication device 102 may or
may not enter a comparable low-power mode.

[0028] Another implementation of the concepts is illustrated in the
process shown in FIG. 3, which may be carried out by the processor 144 of
the remote user interface device 132. At the outset of the process (300),
the remote user interface device 132 may be activated and the second
communication link 142 may be established (302), as described previously.
A timer may be initialized (304), but in this illustration, the timer
keeps track of the extended period rather than the delay period.
(Techniques for management of the timer that keeps track of the extended
period may be applied to the process shown in FIG. 2). In this variation,
the remote user interface device 132 need not request a motion message
from the portable communication device 102. Instead, the processor 110 in
the portable communication device 102 may autonomously check the
accelerometer 150 periodically (e.g., every two seconds) and send a
motion message to the remote user interface device 132 whenever a change
in motion (or motion state) occurs. The processor 110 may determine the
validity of the motion signal from the accelerometer 150, as mentioned
previously. The portable communication device 102 may also send a motion
message to the remote user interface device 132 when no change in motion
has occurred, or may send a motion message periodically, or may send a
motion signal triggered by an event other than motion.

[0029] In the illustrative process shown in FIG. 3, the processor 144 of
the remote user interface device 132 may be operable not to make any
determinations about motion until a motion message is received from the
portable communication device 102 (306). After receiving that motion
message, however, the processor 144 receives a motion signal from the
second accelerometer 152 (308) and determines whether the remote user
interface device 132 is or is not moving (310), as described previously.
If the remote user interface device 132 is moving, the timer keeping
track of the extended period is reset to zero (312) and the process
loops.

[0030] When the processor 144 determines, as a function of the motion
signal from its accelerometer 152, that the remote user interface device
132 is not moving and the processor 144 further determines, as a function
of the motion message received from the portable communication device
102, that the portable communication device 102 is moving (314), the
processor 144 may terminate the communication link 142 (316) and may put
the remote user interface device 132 into a low-power mode (318). When,
however, both devices 102, 132 are stationary, the processor 144 may
determine whether the extended period (e.g., two hours) has elapsed
(320). In the event the extended period has not elapsed, the timer is not
reset, but the process loops. In the event the extended period has
elapsed, the processor 144 may terminate the communication link 142 (316)
and may put the remote user interface device 132 into a low-power mode
(318).

[0031] Many stages in the process depicted in FIG. 3, although being
depicted as being carried out by the remote user interface device 132,
may also be carried out by the portable communication device 102. In
brief, the processor 110 of the portable communication device 102 may be
operable not to make any determinations about motion until a motion
message is received from the remote user interface device 132. When such
a motion message is received, the processor 110 may determine (based upon
a motion signal from accelerometer 150) whether the portable
communication device 102 is moving, and may also determine whether the
remote user interface device 132 is moving (based upon a motion message
from the remote user interface device 132). The processor 110 may
terminate (or may maintain) the communication link 142 based upon the
motion (or lack of motion) of the devices 102, 132.

[0032] The processes described herein may be embodied as machine-readable
instructions that may be cause a processor (such as processor 110 or
processor 144) to carry out one or more functions. The instructions may
be stored in one or more tangible and nontransient media, such as optical
disk, magnetic tape, flash memory drive, and the like.

[0033] One or more embodiments of the described herein may result in one
or more benefits, some of which have been discussed already. In addition
to the convenience and power conservation that may be realized, one or
more embodiments may be implemented flexibly on a wide range of portable
communication devices and remote user interface devices. The portable
communication devices and remote user interface devices may cooperatively
operate even if they do not operate in exactly the same way (e.g., they
may have different kinds of motion sensors). The circuitry and hardware
useful for implementing the concepts (e.g., accelerometers) is relatively
inexpensive, small and lightweight (size and weight are especially of
interest when a device is a handheld device). One or more embodiments
support tailoring processes to a user's own preferences, e.g., a user may
set his/her own extended time period.

[0034] The foregoing description was primarily directed to a certain
embodiments of the present concepts. Although some attention was given to
various alternatives, it is anticipated that one skilled in the art will
likely realize additional alternatives that are now apparent from the
disclosure of these embodiments. For example, the order of some of the
procedures depicted in FIGS. 2 and 3 may be unimportant, and some of the
steps may be optional. Accordingly, the scope of the coverage should be
determined from the following claims and not limited by the above
disclosure. In the claims, terms such as "first," "second," "third" and
the like are used to distinguish between repeated or comparable or
like-named elements, and are not intended to impose any limitation of
order, priority, or any temporal limitation.

Patent applications by Kevin Howard Orr, Elmira CA

Patent applications by Sean Elliott Wilson, Kitchener CA

Patent applications by Vahid Moosavi, Kitchener CA

Patent applications by RESEARCH IN MOTION LIMITED

Patent applications in class Including other radio communication system (e.g., cordless telephone, paging, trunking, etc.)

Patent applications in all subclasses Including other radio communication system (e.g., cordless telephone, paging, trunking, etc.)